[R] Color Nodes

[Jeff Reichman]

Yes Rui that will work for my needs thank you

-----Original Message-----
From: Rui Barradas <ruipbarradas using sapo.pt> 
Sent: Wednesday, October 26, 2022 4:40 PM
To: reichmanj using sbcglobal.net; R-help using r-project.org
Subject: Re: [R] Color Nodes

Às 21:37 de 26/10/2022, Jeff Reichman escreveu:
> R-Help
> 
>   
> 
> For those of you who use igraph is there a way to highlight (color) 
> particular notes. For example if I want to color the "Peter" node red 
> and everything else blue  or leave default) how would I do that or can 
> I do that. Seems as though I might create an attribute column - maybe??
> 
>   
> 
> Jeff
> 
>   
> 
> library(igraph)
> 
>   
> 
> # define links in data
> 
> edges <- rbind(c("Dave", "Jenny"), c("Peter", "Jenny"), c("John", 
> "Jenny"), c("Dave", "Peter"), c("Dave", "John"), c("Peter", "Sam"), 
> c("Sam", "Albert"), c("Peter", "John"))
> 
>   
> 
> # generate and plot graph
> 
> # set argument directed = FALSE in graph.edgelist() to plot an 
> undirected graph.
> 
> g <- graph.edgelist(edges, directed = FALSE)
> 
> plot(g, vertex.size = 1, vertex.label.dist = 0.5)
> 
> 
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> 
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Hello,

After creating the graph, set the vertices colors by subsetting V(g).
Here are two exaples, the first color Peter red and leave the others with their default color. The second, color the other vertices blue.



V(g)["Peter"]$color <- "red"

plot(g, vertex.size = 20, vertex.label.dist = 0.5,
      vertex.color = V(g)$color)

V(g)$color <- "blue"
V(g)["Peter"]$color <- "red"
plot(g, vertex.size = 20, vertex.label.dist = 0.5,
      vertex.color = V(g)$color)



Hope this helps,

Rui Barradas